Crank-shaft for velocipedes.



Patented Oct. 3, |899.

F C ATHERTDN GBNK SHAFT FOB VELUCIPEDES. (Application led Dee. 17, 1898.)

FISHER O. ATIIERTON, OF BUFFALO, NEW YORK.

CRANK-SHAFT FOR VELOCIPEDES.

SPECIFICATION forming part of Letters Patent No. 634,256, dated October 3, 1899.

Application filed December 17,1898. Serial No. 699,542- (ND model.)

1'0 @ZZ whom it may concern:

Beit known that I, FISHER C. ATHERTON, a citizen of the United States, residing at Buffalo, in the county of Erie and State of New York, have invented new and useful Improvements in Crank-Shafts for Velocipedes, of which the following is a specification.

This invention relates to crank-shafts having a detachable crank, and more especially to shafts having a tapering flat-sided seat upon which the detachable crank is iirmly clamped by a screw-nut applied to the screwthreaded end of the shaft. In such shafts the detachable crank sometimes becomes so tightly bound upon the tapering seat of the shaft as to render its removal very difficult.

The object of my invention is to so construct and combine the clamping-nut with the detachable crank that it serves to loosen as well as tighten the crank, thereby facilitating the removal of the crank without mate rially increasing the cost of the attachment.

In the accompanying drawings, Figure l is a fragmentary sectional elevation of a crankshaft embodying my invention. Fig. 2 is an outside view of the detachable crank, the end of the shaft, and the clamping-nut. Figs. 3 and 4 are cross-sections in lines 3 3 and 4 4, Fig. l. Fig. 5 is a detached central section of the clamping-nut, showing the pins retracted into the bore of the nut preparatory to inserting the nut in the recess of the crank-hub.

mounted on the crank-shaft, and c the righthand cone, which may be mounted on the externally-screw-threaded hub cl of the detachable crank. The inner portion of the bore or socket of the crank-hub is tapered and constructed of angular or nat-sided cross-section and iitted upon the correspondinglyshaped end portion or seat e of the crankshaft.

f is the screw-nut whereby the detachable crank is clamped upon the shaft and which engages with the screw-threaded end of the shaft. This clamping-nut, which is circular in form, is countersunk in a corresponding recess g, formed in the outer face of the crank-hub, and abuts against an internal shoulder g', formed at the junction of the recess and the tapering socket of the crankhub, so that upon turning the nut forwardly it forces the crank upon the end of the shaft. The nut is provided in its outer face with nicks or notches forV turning it with a suitable Wrench. In order to cause this same nut to loosen and withdraw the crank from its seat on the shaft, the nut, although permitted to turn in the crank -hub, is held against axial or endwise movement therein, so that upon turning the nut backwardly it draws the hub off its seat. The means shown in the drawings for confining the clampingnut against endwise movement consists of radial pins or projections h, projecting from diametrically opposite sides of the nut and engaging in an annular groove or depression e', formed in the circular wall of the nut-recess g, as shown in Figs. l and 4. These pins are arranged loosely in openings extending radially from the bore to the surface of the nut and are held in their projected position by the screw-stem of the crank-shaft. In interlocking the nut with the detachable crank the pins of the nut are pushed into the bore thereof far enough to bring their outer ends flush with the edge of the nut, as shown in Fig. 5. The nut is then placed in its recess in the crank-hub, and the pins are pushed outward, so as to project into the annular groove i of the hub, in which position they are confined, when the hub is passed over the end of the shaft and the nut is engaged with the screw-threaded end of the shaft.

The loose pins h, while preventing the nut from moving lengthwise of the crank-hub, also act as rollers which reduce the friction of the pins against the walls of the annular groove.

The pins 7L are preferably fitted in the annular groove fi with sufficient looseness to al' low the screw-nut to abut against the shoulder g' of the crank-boss before the pins come in contact with the inner Wall of said groove, so as to relieve the pins from the strain of clamping the detachable crank upon the shaft.

As the sanie nut is used both for tightening and loosening the detachable crank, my improvement is very simple in construction and convenient in use,

I claim as my invention* The combination with a crank-shaft having a screw-threaded end, of a detachable crank applied to said shaft and having in the outer portion of its hub-bore an annular recess which is provided in its Wall with an annular ber, '1898.

FISHER C. ATHERTON. Witnesses:

JNO. J. BONNER, ELLA R. DEAN. 

